The riff comes from Careless Whisper, released in 1984 by George Michael and Wham!, with the famous saxophone solo played by Steve Gregory. Originally a sincere pop ballad about guilt and regret, the solo was later detached from the song and reused online as shorthand for anything supposedly sexy or smooth. Through the 2000s and 2010s it spread across YouTube edits, memes and soundboards as the universal cue for a cheesy romantic moment, and it remains instantly understood even without the vocals.